I have been driving without registration for about 2-3 months with no problems..lucky?

I know the thread is long, but all the info is there. The problem isnt because of not registering the battery, although you will not get optimal life/performance from the battery if you didnt register it. Not registering a battery isnt going to cause the BST cable to pop off or the battery to explode.

But that can only inherently tell the system that the same battery design and capacity has been installed.

Unless Ah valuation has been provided, it can only revert to what was originally programmed.

Now, going up in Ah (capacity) should be a non-issue. If the system wants to maintain the battery at about 80% SOC, and then put energy in, what it will end up finding out is that when it puts energy in, there is more capacity to put even more in. The SOC is determined by evaluation of voltage, which under load has to utilize an estimation for cell impedance in order to be correct (Vt=Voc-IR). If a smaller battery was installed, the logic should still cut out based upon SOC, but the conditions may be such that it causes overcharge conditions or puts too much energy in too quick.

Now I have a 135i, and Im just reading about the BMW batteries. I think mine is black, but Ill have to check. What Im trying to understand even after reading 18 pages is the actual difference between programming and registering... From there Ill go figure if the E8x needs it like the E9x.

Its the same for an E8x. If you go from lead acid to agm (white to black) you need to program. If you change capacity with the same style battery, you only register it.

Quote:

Originally Posted by JHZR2

But that can only inherently tell the system that the same battery design and capacity has been installed.

Unless Ah valuation has been provided, it can only revert to what was originally programmed.

Now, going up in Ah (capacity) should be a non-issue. If the system wants to maintain the battery at about 80% SOC, and then put energy in, what it will end up finding out is that when it puts energy in, there is more capacity to put even more in. The SOC is determined by evaluation of voltage, which under load has to utilize an estimation for cell impedance in order to be correct (Vt=Voc-IR). If a smaller battery was installed, the logic should still cut out based upon SOC, but the conditions may be such that it causes overcharge conditions or puts too much energy in too quick.

Now I have a 135i, and Im just reading about the BMW batteries. I think mine is black, but Ill have to check. What Im trying to understand even after reading 18 pages is the actual difference between programming and registering... From there Ill go figure if the E8x needs it like the E9x.

But that can only inherently tell the system that the same battery design and capacity has been installed.

Unless Ah valuation has been provided, it can only revert to what was originally programmed.

Now, going up in Ah (capacity) should be a non-issue. If the system wants to maintain the battery at about 80% SOC, and then put energy in, what it will end up finding out is that when it puts energy in, there is more capacity to put even more in. The SOC is determined by evaluation of voltage, which under load has to utilize an estimation for cell impedance in order to be correct (Vt=Voc-IR). If a smaller battery was installed, the logic should still cut out based upon SOC, but the conditions may be such that it causes overcharge conditions or puts too much energy in too quick.

Now I have a 135i, and Im just reading about the BMW batteries. I think mine is black, but Ill have to check. What Im trying to understand even after reading 18 pages is the actual difference between programming and registering... From there Ill go figure if the E8x needs it like the E9x.

Thanks!

Reviving old thread since google brought me here... I am curious if you were actually able to figure out the difference of programming/coding vs registration?

The only thing that really matters is to get a RC (Reserve Capacity) close to the original battery. You really only have a hand full of charging profiles that we can use on these cars:

Type:
* AGM/non_AGM (the reason you want to choose the correct type is because AGM batteries don't like to be charged at high voltages like lead acid batteries often are. Also, lead acid batteries don't like to be deep cycled like AGM's do. That's why choosing the wrong type will be the cause of premature failure of the battery).

Formula for Calculating the AH for the car to be coded to for your replacement battery:
(Reserve Capacity / 2) + 16 = AH

So on my original battery I see the following specs
CA: 720
CCA: 720
RC: 160
AH: 90

I believe BMW took some liberty with those "specs", the only numbers which I think are "real" are the RC (Reserve Capacity) and the CCA (Cold Cranking Amps). Because the only numbers we care about are those exact values. CA (Cranking amps) is always going to be greater than the CCA (Cold Cranking Amps) on any replacement battery so that's why they set it to the lower value for both meaning it's "at least 720 CA and at least 720 CCA". I also believe the battery I have based on the RC of 160 is actually a 96 AH battery: (160 RC/2) = 80 + 16 = 96 AH, but they labeled it as a 90AH to make it easier for the tech to know which battery profile to have the car coded to... in this case we would use the 90AH "profile". The only other item I haven't gone into detail is if I had an AGM or non_AGM battery. In this case if I had a lead acid battery in my car I would want my car coded for a 90AH but if I was using the AGM battery instead with same or better specs then I would want the 90AH_AGM

You could just code the car with the battery type set to the correct charging profile... but if someone were to ever re-code your car to the VO... you would go back to the original specs of your car. The correct way is to update the VO (remove old profile setting and add new profile setting) with the correct battery profile and then re-code your car. Finally, register the battery using the BMWLogger tool (free from smooth1). Battery registration basically is the act of wiping all the old battery history (past 5 days) and logging the mileage at which you changed the battery.

if your replacement battery can use the same charging profile you already have programmed in your car... then you don't need to do anything other than the simple registration which is free with a coding cable from ebay and the free BMWLogger software from Smooth1.

Please send a few bucks donation to Smooth1 if you use his free software. Supporting his efforts will probably get more free stuff in future BMWLogger builds. Even if it is something as simple as $1 or $5 each time someone registers a battery... it adds up and helps the community at large.

I haven't bothered to read this whole thread.... 18 pages yikes. But this happened to me with a sears diehard in a volvo once. Batteries can give off H2 from the chemical reaction between the acid and the lead, if it finds a spark you get this.

One potential root cause to this was the battery vent tube was either not re-installed when the op replaced his battery or it fell off, resulting in H2 getting into the trunk cavity and finding either a hot wire or a spark.

I haven't bothered to read this whole thread.... 18 pages yikes. But this happened to me with a sears diehard in a volvo once. Batteries can give off H2 from the chemical reaction between the acid and the lead, if it finds a spark you get this.

One potential root cause to this was the battery vent tube was either not re-installed when the op replaced his battery or it fell off, resulting in H2 getting into the trunk cavity and finding either a hot wire or a spark.

Go back and read. The battery did not explode. The BST cable deployed (which its made to do) due to the battery cable was left loose on the battery post. This causes arching and resistance changes. The car thought it was an accident and deployed the BST because of the archine (cuts off power @ the B+ cable in case of an accident) Its like a mini airbag.

Also for the register vs program thing. Its been talked about 1000 times

Can I ask a question on a similar theme? I have a (UK spec) 118i Auto that I intend to keep at my holiday home; so it will be used only occasionally. There is no mains electric in the garage where it will be stored so I cannot leave it on a float charge.

With my previous cars I have simply fitted a battery cut off / disconnect switch but now I am reading all this stuff about registering the battery and the electrics I am wondering what the implication of the battery being disconnected e.g. for 3 months and then reconnected as necessary? Will the ECU "remember" its a 70 amp battery? Will there be other issues? I know the time and date functions will go down and how to reset them; but will there be anything more sinister?

Can I ask a question on a similar theme? I have a (UK spec) 118i Auto that I intend to keep at my holiday home; so it will be used only occasionally. There is no mains electric in the garage where it will be stored so I cannot leave it on a float charge.

With my previous cars I have simply fitted a battery cut off / disconnect switch but now I am reading all this stuff about registering the battery and the electrics I am wondering what the implication of the battery being disconnected e.g. for 3 months and then reconnected as necessary? Will the ECU "remember" its a 70 amp battery? Will there be other issues? I know the time and date functions will go down and how to reset them; but will there be anything more sinister?

Good question!

As someone who is involved in the engineering of battery systems as a day job, I'll give my professional opinion, not just anecdotal evidence.

Batteries undergo ageing and degradation in a number of ways. First is calendar ageing. That is, chemical reactions that degrade the battery, regardless of if it is used or not. Because reactions are temperature dependent, the main factor there is storage temperature. Second is cyclic degradation. That is, degradation because the number of cycles of a battery are finite. Lead acid batteries of all types (flooded and VRLA) are all relatively poor in terms of cycle life; the saving grace for a starting battery in a car is that it is not discharged deeply. Shallow, slight discharges can be measured in the thousands, deep ones in the tens to low hundreds, depending upon other factors. The third is related to use - similar to cycling, but also more dependent upon rates of operation, conditions of maintenance when used, etc.

So here's the thing. As I understand it, the cars have the size of the battery is programmed into the firmware. The replacement of the battery is also refreshed in the firmware. The wild card is if the current state of ageing is based upon anything other than a calendar life since it was last reset. It is not clear if the algorithm is truly an algorithm, or just a lookup table. Further, it isn't clear if any details stored are in volatile or nonvolatile memory.

Assuming everything is maintained in nonvolatile memory (data isn't wiped out when power is removed from the computer), then disconnecting the battery is the best bet. It will minimize the loss in charge, as the worst thing for any type of lead acid battery is to spend ANY time at any place less than 100% charged. You want to minimize this by preventing any parasitic loads (by disconnecting). All batteries self-discharge internally as well, which you can't help, and will happen when the car sits. Often the rates can be slow, but they are pretty high for lead batteries.

If the assumptions above are correct, I'd disconnect the battery to minimize loss of charge, and then recharge the battery before using the car. Depending upon the state of the battery, it may be best to remove it from the car so it can be charged before even trying to start the car. You can (I do) install a charging lead into the car to make charging the battery quick and easy. Even doing this, the battery will degrade faster, but you'll be easier on the battery,and more importantly, on the alternator and other vehicle electronics,then if you just leave it.

IF the point on the charging map is wiped out when you disconnect power, then you might want to leave it connected to see how it does. I'd then try to fit a solar maintainer if possible to help give a bit of charge. I'd definitely want a scan tool capable of registering new batteries if this were the case, as I believe you'll be doing it fairly often.

Regardless, having a good quality, multi-stage battery charger is imperative, as I'd be topping the battery fully and treating it right as much as possible when you're there.

Can I ask a question on a similar theme? I have a (UK spec) 118i Auto that I intend to keep at my holiday home; so it will be used only occasionally. There is no mains electric in the garage where it will be stored so I cannot leave it on a float charge.

With my previous cars I have simply fitted a battery cut off / disconnect switch but now I am reading all this stuff about registering the battery and the electrics I am wondering what the implication of the battery being disconnected e.g. for 3 months and then reconnected as necessary? Will the ECU "remember" its a 70 amp battery? Will there be other issues? I know the time and date functions will go down and how to reset them; but will there be anything more sinister?

Can you use a solar-powered float charger? Is there a sun-facing spot in the storage location that you can mount a small solar panel and use a solar-powered battery maintainer. I use one for my lawn equipment in my non-electrified shed.

I just ordered one! It might work but I can't rely on it. My garage is under the apartment block although I am next to the ramp and there is 'some' sunlight. But it's worth a try.
With all my previous cars (Jeep Cherokee, BMW Compact, Toyota Rav4) I just used a battery disconnect switch and never had a problem. I left my Jeep once for 18 months and when I reconnected it started first time!
I have now tried disconnecting the battery on my 118i for 24 hours and re-connecting. No error messages, just the clock to reset. I work at a BMW dealer so I will get the fault memory checked tomorrow. But I am hoping that all will be OK.
Another question: my battery disconnect switch is quite simple, you remove the clamp from the negative terminal, replace it with the switch and then put the clamp on the other side of the switch. Contact is made by screwing a brass bolt into the switch (by hand - it's on a plastic wheel). I have used these switches for 10 years without problem but what would happen if the switch unscrewed and disconnected at high speed? Would it trigger the BMW safety system on the positive terminal? Would it fry the electrics? Etc